Benzodioxincarboxamides

ABSTRACT

Certain 2,3-dihydro-1,4-benzodioxin-2-carboxamides, useful as lipogenesis inhibitors in mammals.

This application is a continuation-in-part of application Ser. No.951,536, filed on Oct. 16, 1978, now abandoned.

DESCRIPTION OF THE INVENTION

It has been found that lipogenesis in mammals is inhibited by certain2,3-dihydro-1,4-benzodioxin-2-carboxamides, of the formula ##STR1##wherein R is a moiety which is one of: (hydroxyimino)methyl,1-(hydroxyimino)ethyl, (methoxyimino)-methyl, 1-(methoxyimino)ethyl,acetamido, benzamido, and 2-methyl-4-thiazolyl.

In Formula I, the dotted lines from the moiety R to the carbon atoms inthe ring are intended to indicate that the moiety can be bonded to thecarbon atom at the 6-position, or a carbon atom at the 7-position, ofthe ring structure.

Methods by which the compounds of this invention can be preparedordinarily produce mixtures of the 6-substituted and 7-substitutedspecies. Such mixtures, as well as deliberate mixtures, of the 6- and7-substituted species, as well as each of the individual 6- and7-substituted species, are contemplated in this invention.

Chirality exists in the compounds of Formula I due to the asymmetricstructural configuration at the 2-position of the2,3-dihydro-1,4-benzodioxin ring. As a result, each of these compoundsexists in the forms of two optical isomers. The individual isomers havenot been separated, so that their respective activity as lipogenesisinhibitors has not been determined. The invention contemplates each ofthe individual active isomers, as well as racemic, and other mixturesthereof.

Typical, exemplary, individual species of the compounds of Formula I,and their preparation, are described in actual examples set outhereinafter. Other typical, exemplary, individual species are those,referring to Formula (I), below, wherein the moiety R, and its positionon the ring structure, are as follows:

    ______________________________________                                        ______________________________________                                        7-(hydroxyimino)methyl                                                        7-(methoxyimino)methyl                                                        ______________________________________                                    

and the 6-position counterparts of these species.

The compounds of Formula I can be prepared by the following procedures.

In each of the following examples, the identities of the products, andthe intermediates involved, were confirmed by appropriate elemental andspectral analyses.

EXAMPLE 12,3-dihydro-7-(1-hydroxyimino)ethyl)-N-(2-propenyl)-1,4-benzodioxin-2-carboxamide(1)

400 ml of a mixture of 1:8 v/v glacial acetic acid in water was added intwo portions to a stirred mixture of 35 g of 4-(chloroacetyl)catechol in300 ml of ethanol. At 10-minute intervals, four 10 g portions of 90%zinc dust were added, the mixture being held below about 45° C. Themixture then was stirred for 2 hours at 30°-40° C. and allowed to standover a weekend. The liquid phase was decanted and stripped to a quarterof its volume under reduced pressure. The residue was extracted withether. The ether extract was washed with sodium bicarbonate solution.The solvent was evaporated. The solid residue was recrystallized fromtoluene to give 4-acetylcatechol (1A), mp: 118°-119° C.

150 g of ethyl 2,3-dibromopropionate was added over a 3-hour period to astirred slurry of 96 g of 1A, 234 g of potassium carbonate and 600 ml ofacetone. The temperature of the mixture rose from 23° C. to 40° C. Themixture then was refluxed (55° C.) for 19 hours, and filtered. Theacetone was evaporated from the filtrate under reduced pressure. Theresidue was distilled to give ethyl 7(and6)-acetyl-2,3-dihydro-1,4-benzodioxin-2carboxylate (1B) as a colorlessliquid, bp: 165°-166° C., 0.1 Torr.

A mixture of 18 g of 1B, 75 ml of methanol, 5.2 g of hydroxylaminehydrochloride, 50 ml of water and 4.0 g of sodium carbonate was heatedon a steam bath for 35 minutes and allowed to stand overnight. The solidwhich formed was separated and recrystallized from benzene to give ethyl2,3-dihydro-7(and 6)-(hydroxyimino)ethyl)-1,4-benzodioxin-2-carboxylate(1C), mp: 111°-113° C.

3 g of 1C and 5 g of 2-propenylamine were mixed and the mixture was heldat 25° C. for 4 days. The excess amine was evaporated under reducedpressure. The residue was triturated with hot hexane. The hexane phasewas decanted and the residue was recrystallized from a 1:1 v/v mixtureof hexane and ethyl acetate, to give 1, as a white solid, mp: 140°-142°C.

EXAMPLE 22,3-Dihydro-7-(1-(methoxyimino)ethyl)-N-2-propenyl-1,4-benzodioxin-2-carboxamide(2)

22.8 g of 1B was dissolved in 100 ml of ethanol. A solution of 7.94 g ofmethoxylamine hydrochloride and 5.5 g of sodium carbonate in 75 ml ofwater was added. The mixture was heated and stirred at refluxtemperature for 4 hours, then was allowed to cool and held at roomtemperature over a weekend. The mixture was diluted with 50 ml of waterand the solvents were evaporated. The residue was extracted with ether.The extract was dried (MgSO₄) and filtered. The solvent was evaporatedfrom the filtrate and the residue was chromatographed over silica gel,using a 1:1 v/v mixture of ether and hexane as eluent. The majorabsorption band was worked up to give an oil, which was distilled in aKugelrohr apparatus to give ethyl2,3dihydro-7-(1-methoxyimino)ethyl-1,4-benzodioxin-2-carboxylate (2A),bp: 136°-138° C. (0.12 Torr.).

7.9 g of 2-propenylamine was added drop-by-drop to a mixture of 6.4 g of2A and 30 ml of ethanol at room temperature. The resulting mixture wasstirred at room temperature overnight. The volatile materials wereevaporated under reduced pressure and the residue was distilled to give2, as a liquid, bp: 156°-158° C. (0.15 Torr.).

EXAMPLE 32,3-Dihydro-7-(2-methyl-4-thiazolyl)-N-(2-propenyl)-1,4-benzodioxin-2-carboxamide(3)

A solution of 56.0 of alpha-chloro-3',4'-dihydroxyacetophenone in 400 mlof 1,2-dimethoxyethane was added drop-by-drop to a soution of 23.0 g ofthioacetamide in 300 ml of 1,2-dimethoxyethane. The mixture was heatedand refluxed for 20 hours. The precipitate which formed was collectedand dried. The residue was suspended in water and dilute (10%) sodiumhydroxide solution was added until the pH of the mixture was about 6.The precipitate was collected and dried to give4-(2'-methyl-4'-thiazolyl)catechol, (3A).

40.9 g of ethyl 2,3-dibromopropionate was added drop-by-drop to amixture of 31.1 g of 3A, 53.9 g of anhydrous potassium carbonate and 750ml of acetone, at reflux. The resulting mixture was heated was heated atreflux for 18 hours, then was filtered. The filtrate was concentrated,the residue dissolved in 500 ml of ether and the resulting mixture wasfiltered. The filtrate was washed sequentially with water, 5% sodiumhydroxide solution, and water. The ether phase was separated, dried(MgSO₄) and concentrated. The resulting oil was chromatographed onsilica gel, using a 1:1 v/v mixture of hexane and ether as eluent. Thefraction containing the product was extracted with ether, and the etherwas evaporated under reduced pressure to give an oil. The oil wasdistilled to give ethyl 6(and7)-(2'-methyl-4'-thiazolyl)-2,3-dihydro-1,4-benzodioxin-2-carboxylate(3B), bp: 168°-172° C. (0.15 Torr.).

22.4 g of 2-propenylamine was added drop-by-drop to a solution of 70 gof 3B in 200 ml of ethanol at room temperature. The mixture was stirredat room temperature overnight. The volatile materials were evaporatedand the residue was chromatographed on silica gel, using 1:1 v/v mixtureof hexane and ether as eluent. The lower Rf band was extracted withether. The ether was evaporated and the residue was dried to give 3.

EXAMPLE 47-(Acetylamino)-2,3-dihydro-N-(2-propenyl)-1,4-benzodioxin-2-carboxamide(4)

68 g of phosphorus pentachloride was added in portions over a 15-minuteperiod to a stirred solution of 50 g of 1C in 1000 ml of chloroform. Themixture was refluxed for 2 hours, allowed to cool while being stirred,then, with stirring, was poured into 1000 ml of ice water. The organicphase was separated, washed with water, then with 10% sodium bicarbonatesolution, dried (MgSO₄) and filtered. The solvent was evaporated fromthe filtrate under reduced pressure. The residue was triturated with 60ml of ethanol. The mixture was stored in a freezer overnight. The solidwhich formed was collected and washed with ethanol, then ether, anddried under reduced pressure. The product was dissolved in 100 ml of hotethanol; the solution was filtered through charcoal and chilled in afreezer over a weekend, and filtered. The solid was refluxed in 200 mlof ether for 1/2 hour and the resulting mixture was filtered. The solidwas chromatographed over silica gel using chloroform as eluent. Theappropriate fractions were extracted with chloroform and the solvent wasevaporated from the extract under reduced pressure. The residue wasagain chromatographed over silica gel, using chloroform as eluent. Theappropriate fractions extract under reduced pressure. The residue wasagain chromatographed over silica gel, using chloroform as eluent. Theappropriate fractions were extracted with chloroform and the solvent wasevaporated from the extract under reduced pressure. The residue wasdissolved in 90 ml of hot ethanol, the solution was filtered throughcharcoal and chilled in a freezer overnight. The solid was collected,dissolved in hot ethanol; the solution was filtered through charcoal andchilled in a freezer. The solid was collected, ground and dried to giveethyl 7-(acetylamino)-2,3-dihydro-1,4-benzodioxin-2-carboxylate, (4A),mp: 146°-147° C.

A mixture of 3.5 g of 4A, 30 ml of 2-propenylamine and 25 ml of ethanolwas stirred for 18 hours. The volatile materials were evaporated underreduced pressure and the residue was co-evaporated with ethanol until asolid formed. The solid was dissolved in a minimum amount of hotethanol. The solution was filtered through charcoal, chilled and thesolid product was separated. The solvent was evaporated under reducedpressure. The residue was held in a freezer over a weekend. 20 ml ofwater was added with stirring and the solid was collected. The solid wasstirred with a further 20 ml of water; the solid was collected, washedwith ether, and triturated with hexane until a gum precipitated. Thesolvent phase was separated. The gum was again triturated with hexaneand the solvent phase was separated. The two extracts were combined; thesolvent was evaporated under reduced pressure, and the residue waswashed with ether, then dried to 4, as a solid, mp: 138°-140° C.

Other individual species of the compounds of Formula I can be preparedby treating the appropriate ester precursors with an excess of ammoniumhydroxide or 2-propenylamine, as illustrated in Examples 1-4.

The species wherein R is benzamido can be prepared by treating thespecies wherein R is amino (which can be prepared by hydrolysis of thespecies wherein R is acetamido) with benzoyl chloride.

The carboxamides of Formula I have been found to inhibit lipogenesis intissues of mammals. The manner in which they cause this effect is notknown with certainty; it is believed that they interfere with thesynthesis of fatty acids in the tissues. Their effectiveness for thispurpose has been ascertained by immersing samples of swine adiposetissue in a liquid medium containing radioactive glucose and the testchemical for a period of time, then isolating the lipid from the treatedtissue and determining the incorporation of the radioactive carbon intolipid by means of scintillation counting techniques. These tests wereconducted in swine adipose tissues because in swine, the primary site oflipogenesis--i.e., fatty acid synthesis--appears to be adipose tissue.

Described in more detail, the tests were conducted according to thefollowing general procedure:

150 milligrams of slices of swine adipose tissue were incubated at 37°C. for 2 hours with shaking in 3 milliliters of Krebs-Ringer bicarbonatesolution containing one-half the normal calcium ion concentration, 60micromoles of glucose, 0.5 micro-Curie of glucose-U¹⁴ C, and 300microunits of insulin, and 5% dimethyl sulfoxide (DMSO). The testcompounds were added as a solution of suspension in DMSO and werepresent at a concentration of 100 micrograms per milliliter of theincubation mixture.

The incubation was terminated by addition of 0.25 milliliter of 1 Nsulfuric acid. The resulting mixture was extracted with a total of 25milliliters of chloroform/methanol (2:1 v/v). The extracts were washedaccording to Folch et al. (J. Biol. Chem. 226, 497-509 (1957)), airdried, and counted in a liquid scintillation counter with 15 millilitersof counting fluid (two parts toluene containing 0.4% w/v New EnglandNuclear Omnifluor/1 part Triton X-100). The tests were conducted intriplicate and were accompanied by control tests in which allingredients, proportions and conditions were the same except that notest compound was included. From the data obtained were calculated thepercent inhibition of lipid synthesis by the test compounds in eachcase. The data obtained from the tests are set out in Table 1, as thepercent inhibition of lipogenesis compared to the results obtained inthe control tests wherein only the test compound was omitted.

                  Table I                                                         ______________________________________                                        Compound No.       Percent Inhibition                                         ______________________________________                                        1                  70                                                         2                  71                                                         3                  76                                                         4                  83                                                         ______________________________________                                    

The carboxamides of Formula I can be used to control lipogenesis inmammals such as, for example, pets, animals in a zoo, livestock,fur-bearing animals and domestic animals, including, but not limited todogs, cats, mink, sheep, goats, swine, cattle, horses, mules anddonkeys. The effect is obtained by administering an effective amount ofone or a mixture of two or more of the carboxamides orally orparenterally to the animal. They may be administered as such, or as anactive ingredient of a conventional pharmaceutical formulation. They maybe administered orally by any convenient means. Thus, they may be orallyadministered as a drench, by intubation, in the animal's food and water,in a food supplement or in a formulation expressly designed foradministration of the drug. Suitable formulations include solutions,suspensions, dispersions, emulsions, tablets, boluses, powders,granules, capsules, syrups and elixirs. For parental administration,they may be in the form of a solution, suspension, dispersion oremulsion. They can be administered in the form of an implant or othercontrolled sustained release formulation. Inert carriers, such as one ormore of water, edible oil, gelatin, lactose, starch, magnesium sterate,talc or vegetable gum can be used. The dosage of the carboxamide neededto inhibit lipogenesis will depend upon the particular carboxamide used,and the particular animal being treated. However, in general,satisfactory results are obtained when the carboxamides are administeredin a dosage of from about 1 to about 400 milligrams per kilogram of theanimal's body weight. The carboxamide can be administered in a singledose or in a series of doses in the same day, or over a period of days.For any particular animal, a specific dosage regimen should be adjustedaccording to the individual need, the particular carboxamide(s) used asthe inhibitor, and the professional judgment of the person administeringor supervising the administration of the inhibitor. It is to beunderstood that the dosages set forth herein are exemplary only, andthat they do not, to any extent, limit the scope or practice of theinvention.

I claim as my invention:
 1. A compound of the formula ##STR2## wherein Ris a moiety which is one of (hydroxyimino)methyl, 1-(hydroxyimino)ethyl,(methoxyimino)methyl, 1-(methoxyimino)ethyl, acetamido, benzamido, and2-methyl-4-thiazolyl.
 2. A method of inhibiting lipogenesis in a mammal,which comprises administering, to a mammal in need of such treatment,orally or parenterally a lipogenesis inhibiting amount of a compound ofclaim 1.